Pneumatic tool.



No. 727,431. PATENTE) MAY 5`, 1903.

' 0. W. PECK.

PNBUMATIG Tomi'. PPLIUATION FILIJDJULY 17, 19702.

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No MODEL.

A :nn/Hmml WITNESSES ATTORN EY No. 727,431, PATENTE) MAY 5, 1903.v o. W.BECK. PNEUMATIG Tool-. APPLIATIDH FILED JULY 17, 1902.

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ATTGRNEY Yiliarrnn STATES Patented May 5, 1903.

ATENT OFFICE.

CLARENCEIV. PECK, OF ATHENS, PENNSYLVANIA, ASSIGNOR, BY DIRECT AND MESNEASSIGNMENTS, TO IMPERIAL PNEUMATIO TOOL COMPANY,

OF ATHENS, PENNSYLVANIA.

PN EUNIATIG TOOL.

SPECIFICATION forming part of Letters Patent No. 727,431, dated May 5,1903.

I Application filed July 17, 1902- Serial No. 115.958. (No model.)

To @ZZ whom, it inlay concern:

Be it known that I, CLARENCE W. PnoK, a citizen of the United States,residing at Athens, in the county of Bradford andState of Pennsylvania,have in vented certain new and useful Improvements in Pneumatic Tools,of which the following is a specification.

My invention relates to improvements in pneumatic hand-tools wherein areciprocating 1o piston actuated by compressed air or other iiuid underpressure is made to drive various tools such as are used in chipping,calking, drilling, and other operations.

The main feature of my invention relates to the valve mechanism by whichthe movements of the piston are controlled and wherein the valve isarranged concentric with the piston-cylinder in order thattheremay be amaximumpiston travel, together with a minizo mum length of tool; andtheobject of this portion of my invention is to providea valve which shallbe positive and steady in its operation and which will impart a quickchange of stroke to the piston, thereby` increasing 2 5 the number ofblows per minute of the piston upon the head yof the working implement,and, furthermore, to so construct the valvechamber as to provide acushion for the piston upon reaching the end of its rearward 3o Stroke.

Another feature of my invention relates to improvements in thecontrollingvalve, by which the admission of the air to the tool iscontrolled and adjusted, the object of this portion of my inventionbeing to provide a liner and more sensitive adjustment than is presentin the tools now known to me.

Other features of my invention relate to the construction andarrangement of the 4o valve, valve-box, ports, and passages, whereby Iattain improved results, which novel features of constructionwill appearhereinafter and be more particularly pointed out in my claims.

I attain the objects of my improvements by the construction andarrangement of parts, as illustrated in the accompanying drawings,wherein I have shown my invention as applied to apneumatie hammer, andin which- Figure l represents a longitudinal section of mycomplete tool;Fig. 2, a plan view of the same, the rear portion being shown assectioned at right angles to. Fig. l; Fig. 3, a section on an angleintermediate between the sections shown in Figs. l and 2; Fig. 4:,a rear55 View of the cylinder with the other parts removed; Figs. 5, 6, and 7,sectional details of the valve-box and valve, and Figs. 8 and 9 detailsof the throttle-valve.

Like letters refer to like parts throughout 6o the several views.

A represents the cylinder or barrel of the tool, provided at one endwith a socket to receive the shank of a chisel or other implement, andat the other end havinga flange B, with a rearwardly-projecting rim C,against which is set the forward face of the valve-box D, said valve-boxbeing centered by fitting within the rim C. This valve-box is carriedwithin a chamber E, to which is attached the 7o operating-handle F. Theexterior wall of chamber E is screw-threaded to receive the sleeve G andjam-nut H, by which the several parts are assembled and rigidly securedtogether. W'ithin the valve-box D, which is 75 provided with passages,ports, and grooves, as hereinafter described, is a cylindrical valve I,adapted to travel longitudinally therein, the inner diameter of whichcorresponds with the bore of thecylinderA and forms a prolon- 8o gationthereof. This valve is provided with ports and exterior grooves, whichas the valve reciprocates are brought into alinement with the groovesand ports in thevalve-box to permit the admission and exhaust to andfrom the ends of the piston P by way of corresponding passages and portsin the cylinderA, as will hereinafter appear. At the rear of thevalvebox and held between it and the head of chamber E is a angedbushing J, which projects 9o into the valve I, thereby forming achamberj, in which the rear anged portion of the valve I reciprocatesand io and fromy which chamber ports and passages are led to thecylinder through the valve-box, whereby air is alternately admitted toand exhausted from the opposite sides of this anged portion of the valveas the piston P travels back and forth in the cylinder to shift thevalve at the proper periods. roo

The supply-hose is coupled to the handle at K, the air-supply to thetool being controlled by the throttle-valve L, the flanged head of whichseats against the ring M, which is held in place by the bushing K, thevalve being pressed to its seat by the spring N. 'lhe valve is opened bypressing upon the thumb-lever O, which acts upon the valvestem, asindicated. Referring to Figs. 8 and 9, it will be seen that the Valve Lhas three diameters, the smallest diameter forming the stem, thenextlarger diameter ttingthe bore of the ring M, and the largestdiameter forming a head l, which seats against the ring M. The force ofthe air-pressure against said head, in addition to the spring N, holdssaid valve in closed position at all times when not actuated by thethumb-lever O. The shoulder between the stem portion and the next largerdiameter of the valve L is provided with a series of bevels Z', cut atdiiferent angles, whereby when the valve is pressed outwardly first onebevel will open communication from the air-supply to the admissionductc, and then the next less acute bevel, and so on, until the valve isthrown completely open. By this construction of the valve the air isadmitted gradually to the tool, and after a little practice the operatorcan so adjust the thumb-lever O as to admit the air in varyingquantities, according to the speed of the piston travel and force ofblow desired. In addition to this graduated throttle-valve I provide aregulating-valve Q at the head of duct a, which valve is bored tocorrespond with said duct and is provided with a port b, adapted toregister with the admission-passage c in valve-box D. This Valve isthreaded into the handle and is provided with a serrated head S, thebeveled teeth on which are engaged by a correspond'- ing beveledlocking-bolt R, back of which is a coiled spring, whereby said bolt isheld in engagement with said head. By turning the head S in one or theother direction port b will close the opening from duct a into passage cmore or less, as desired, and the valve will be held in this adjustmentby the lockbolt R.

Having thus described the principal parts of my device, the operationthereof Will now be explained in connection with the relativearrangement of the passages, ports, and grooves in valve, valvebox, andcylinder heretofore referred to. In the several iigures the piston P isshown in its outward position and the valve is shown as set for thereturn stroke. To accomplish this stroke of the piston, the air passesfrom the passage c through port d and by way of grooves d' and 'n'through port n into the' passage h, andv thence by way of port h to thefront of the piston, thereby driving the piston to the rear. During thisstroke of the piston the air is exhausted from the cylinder behind thepiston by way of the ports t in the valve I, groove o, port tu, andpassages v and .fr in the valvebox and handle. (See Fig. 3.) As thepiston approaches the end of this rearward stroke the exhaust from portst" will be cut off and the entrapped air will be compressed, and as thereduced portion p of the piston enters the bushing J, which it tssnugly, an effectual air-cushion is produced, which will bring thepiston to a stop without shock upon the hand of the operator. Before thepiston has quite reached the end of this stroke the groove p thereinwill place passages c and g in communication with passages r q (seeFigs. l and 2) by way of ports g fr, thereby admitting live air throughport q to the front face of the flange on valve I. At the same time theend of the piston has passed ports s and u', (see Figs. 2 and 3,)thereby opening communication between the rear of the valve and theexhaust-outlet a; by way of the port j and passages t', t, s, u, and c,and the valve will be shifted to its rearward position. In this positionof the valve the ports t' therein are brought into register with thegroove e', which communicates with the admissionpassage c through theport e, and the air will be admitted to the rear of the piston to forceit forward. During this forward stroke of the piston the exhaust willtake place through port h', passages h 7c, port fm, grooves m', o', ando, which are then in register, port w, and passages u and (See Figs. land 3.) Just before the piston arrives at the end of its forward strokethe ports (see Fig. 2) will be uncovered and live air will pass from thecylinder through passages s t t to the port j in chambery, and theexhaust from in front of the valve in this chamber will be openedthrough port q', passages q and r, port r, groove p, port u, andpassages u, U, and (see Figs. A2 and 3,) upon which the Valve will beshifted to its forward position, as shown in Figs. l, 2, and 3 of thedrawings, and the cycle of operations will be repeated.

It will be noted that there are no differential areas on the valve to beacted upon by the duid-pressure in shifting the valve, but thatadmission and exhaust takes place simultaneously, first on one side andthen on the other side of the valve-flange in chamber j, by reason ofwhich I attain a positive and quick-acting Valve, the pressure upon oneside of the shifting ange being relieved the moment live air is appliedto the other side. While apparently there is a differential area betweenthe front and rear faces of the iange on the valve in chamberj, as amatter of fact this difference of area does not exist, so far as theoperation of the valve is concerned, because when the valve is in itsrearward position the forward rim of the valve is subjected to live-airpressure within the cylinder, and when the live air is admitted to therear of chamber j the areas at each end of the valve corresponding tothethickness of the shell of the valve will be in balance, so that theeffective pressure area on the rear portion of the valve in chamber jwill correl'OO IIO

spend precisely to that on the forward side of the flange.

In order to prevent the valve from fluttering as it is shifted from oneposition to the other, I provide a small port f, leading fromadmission-passage o to chamber j, the diam-` eter and position of thisport being such that in either position of the valve a small openingwill be provided from said passage into the chamber j, whereby live airwill be admitted, so as to force the valve to its seat and hold it therein either position, and this feature I consider as an important item `inmy invention.

By reason of the large admission-ports t'` construction of my tool tothe precise arrangement of the various passages, ports,l

and grooves nor to exact details of construction.

Having thus described my improvements, what I claim as my invention, anddesire to secure by Letters Pat-ent, is-

l. In an impact-tool, the combination of a cylinder, a reciprocatingpiston therein, a cylindrical ported valve movable in line with thepiston in a chamber at one end of the cylinder, and `an enlargement onthe valve traveling in a separate chamber, to and from each side ofwhich motive iinid is admitted and exhausted at each stroke of thepiston to shift the valve.

2. In an impact-tool, the combination of a cylinder, a reciprocatingpiston therein, a cylindrical ported valve movable in line with thepiston in a chamber at one end of the cylinder, a ring or iiange on thevalve traveling in a separate annular chamber, to and from each side ofwhich motive iuid is admitted and exhausted at each stroke of the pistonto shift the valve.

3. In an impact-tool, ythe combinationof a cylinder, a reciprocatingpiston therein, a cylindrical ported valve movable in line with thepiston in a chamber at one end of the cylinder, a bushing projectinginto the valve from the head of said chamber, and an. enlargement onthe-valve traveling in a separate chamber formed thereby, to and fromeach side of which motive fluid is admitted and exhausted at each strokeof the piston to shift the valve.

d. In an impact-tool, the combination of a cylinder, a reciprocatingpiston therein, a cylindrical ported valve movable in lino with thepiston in a chamber at one end of the cylinder, a hollow bushingprojecting into the valve from the head of said chamber, an enlargementon the valve traveling in a separate chamber thus formed, to and fromeach side of which motive iinid is admitted and exhausted at each strokeof the piston yto shift the valve, and a reduced end on' the pistonwhich enters'said bushing on the back stroke to cushion the piston.

5. In an impact-toohthe combination of a cylinder, a reciprocatingpiston therein, a cylindrical ported valve movable in line with thepiston in a chamber at one end of the cylinder, an enlargement on thevalve traveling'A in a separate chamber, to and from each side of whichmotive iiuid is admitted and exhausted at each stroke of the piston toshift the valve, anda port opening into said lastnamed chamber wherebylive :duid is admitted behind said enlargement ateither stroke of thevalve toi-hold it to its seat.

6. In an impact-tooL-the combination of a n cylinder, a reciprocatingpiston therein, fa

valve to control admissionand exhaust to and' from the piston,meanscontrolled by the pis- I ton for shifting the vvalve by the motiveduid, a a'ngdor' enlargement on the valve traveling in a separatechamber, and a port atqa' medial point in the Wall of said chamber inconstant communication with the fluid-supply, Whereby live duid isdirected to one side,

or the other of said ange at each stroke of the valve to hold' it to itsseat.

7. InI an impact-tool, the combination of a cylinder, a reciprocatingpiston therein, a cylindrical valve movable in line with the piston in achaz'nbei` atene end of the cylinder,

a plurality of grooves in the walls of said chamber, admission andexhaust passages and ports leading to and from said grooves, grooves onthe valve acting in conjunction with the.

chamber-grooves whereby the far end of the cylinder is openedalternately to the admission and exhaust, ports through thevalve wherebythe nea-r end of the cylinder is opened to admission and exhaust, theadmissionports in the valve being of larger'area than the exhaust-ports,and the admission-ports and grooves in the valve-chamber for the nearend of the cylinder being of larger area than;4

i those for the far end for the purpose set forth,

and means controlled by the pistonforj'shifting the valve by the motiveHuid.

8. In an impact-tool, the combination of a cylinder, a reciprocatingpiston therein, a cylindrical valve movable in line with the piston in achamber at one end of the cylinder, a plurality of grooves in the wallsof said chamber,admission and exhaust passages and portsleading to andfrom said grooves, grooves and ports in the valve whereby the far andnear ends of the cylinder are opened alter-l nately to the admission andexhaust, an enlargement on the valve traveling in a separateehamber,ports and passages leading from each end of said ehamberfto the cylinderintermediate its ends, and grooves on the passages leading to theadmission and exhaust.

9. In an impact-tool, the combination'of a cylinder, a reciprocatingpiston therein, a cylindrical valve-box centered on the end of saidcylinder, admission and exhaust passages through the valve-boxregistering with corresponding passages in the cylinder walls, grooveson the inner periphery of the valvebox with ports leading to saidpassages, a grooved and ported .valve movable in said valve-box in linewith the piston and forming a prolongation of the cylinder, a flangedbushing held between the end of the valvebox and the'head of aninelosing chamber, i

'chamber in which travels an enlargement on the valve, and ports andpassages leading to and from said chamber, under control of the piston,to the admission and exhaust.

In testimony whereof I have affixed my signature in presence of twowitnesses.

CLARENCE W. PECK.

Witnesses:

' Units@ BROWN,

GEMUNN.

